UV study of copper (II) mixed ligand complexes having pyrazole as one of the ligand

In the present investigation, UV data of four copper (II) mixed ligand pyrazole complexes, i.e., complex I - [Cu(C3H8N2O2)Cl2], complex II - [Cu(C3H14N2O5)(SO4)] complex III - [Cu(C3H8N2O2)I2] and complex IV - [Cu(C3H16N2O6)(NO3)2] have been analysed. The analysed studies of the complexes represent the direct and indirect band gap energy of all studied complexes. The UV data have been analysed using Origin 2019 software. The band gap energy of all studied complexes has been same by direct and indirect band gap energy determination procedure. The results of the study revealed that the presence of SO4 ion enhances the band gap energy in complex II whereas the presence of Cl, I and NO3 ligand suppresses the band gap energy of complex I, III and IV. Keywords: UV, pyrazole, direct, indirect and band gap energy.